regex_notes.txt

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        IDENTIFIERS
===========================
\d im looking for a number
\D im looking for anything but a number
\s im looking for a space
\S im looking for anything but a space
\w im looking for a character
\W im looking for anything but a character
.x im looking for the letter x...eg when looking for a, r'.a'
\b im looking for a whitespace around words
\. a period- can be used as a wildcard(character used as a placeholder of anything else
\ is an escape character

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        MODIFIERS
===========================
they describe identifiers even more
{x,y} im expecting x to y digits or {x} expecting x digits or characters eg \d{1,3} looking for 1 to 3 digits

'\d{4,} looking for a number with 4 and above digits
+ match 1 or more
? match 0 or 1
* match 0 or more
$ match the end of a string
^ match the beginning of a string.
eg ^blog... dont match anything before this word i.e, this word should be the first in a sentence
eg blog$... dont match anything after this word i,e, should be last
when used in a range, it means give me everything but whatever is in the range bracket
eg, give me words in the form b[^a']....word starting with b and followed by any other letter
but not a

When used outside the range, it means 'match the beggining of a line'
eg, only give me words that dont start with capital letters.
^[^A-Z]
| matches either or eg \d{1,3} | \w{5,10} looking for a digit 1 to 3 in length or characters 5 to 10 in length
[] gives range...eg [A-Z] looks for anything with capital letters
[A-Za-z] looks for anything capital or small letters
[A-Z][a-z]* looks for anything starting with caps then followed by 0 or more occurrences of a small letter a to z
[h-m]at looking for words with the first letter in the range of h-m and ends with at
re.match() checks for a match at the beginning of a string
re.search() checks for a match throughout a string